The Command to strike the Enemies' Necks, tighten Their Bonds, and then free Them either by an Act of Grace or for a Ransom
Guiding the believers to what they should employ in their fights against the idolators, Allah says,
فَإِذا لَقِيتُمُ الَّذِينَ كَفَرُوا فَضَرْبَ الرِّقَابِ
So, when you meet those who disbelieve (in battle), smite their necks,
which means, `when you fight against them, cut them down totally with your swords.'
حَتَّى إِذَا أَثْخَنتُمُوهُمْ
until you have fully defeated them,
meaning, `you have killed and utterly destroyed them.'
فَشُدُّوا الْوَثَاقَ
tighten their bonds.
فَإِمَّا مَنًّا بَعْدُ وَإِمَّا فِدَاء
Thereafter (is the time) either for generosity or ransom,
`This is referring to the prisoners of war whom you have captured. Later on, after the war ends and the conflict has ceased, you have a choice in regard to the captives;You may either act graciously toward them by setting them free without charge, or free them for a ransom that you require from them.'
It appears that this Ayah was revealed after the battle of Badr. At that time, Allah reproached the believers for sparing many of the enemy's soldiers, and holding too many captives in order to take ransom from them. So He said then;
مَا كَانَ لِنَبِىٍّ أَن يَكُونَ لَهُ أَسْرَى حَتَّى يُثْخِنَ فِي الاٌّرْضِ تُرِيدُونَ عَرَضَ الدُّنْيَا وَاللَّهُ يُرِيدُ الاٌّخِرَةَ وَاللَّهُ عَزِيزٌ حَكِيمٌ لَّوْلَا كِتَـبٌ مِّنَ اللَّهِ سَبَقَ لَمَسَّكُمْ فِيمَأ أَخَذْتُمْ عَذَابٌ عَظِيمٌ
It is not for a Prophet to have captives of war until he had made a great slaughter (among the enemies) in the land. You desire the commodities of this world, but Allah desires (for you) the Hereafter. Allah is Mighty and Wise. Were it not for a prior decree from Allah, a severe torment would have touched you for what you took. (8;67-68)
Allah's saying,
حَتَّى تَضَعَ الْحَرْبُ أَوْزَارَهَا
until the war lays down its burden.
Mujahid said;
"Until `Isa bin Maryam (peace be upon him) descends."
It seems as if he derived this opinion from the Prophet's saying,
لَاا تَزَالُ طَايِفَةٌ مِنْ أُمَّتِي ظَاهِرِينَ عَلَى الْحَقِّ حَتْى يُقَاتِلَ اخِرُهُمُ الدَّجَّال
There will always be a group of my Ummah victorious upon the truth, until the last of them fight against Ad-Dajjal.
Imam Ahmad recorded from Jubayr bin Nufayr who reported from Salamah bin Nufayl that he went to the Messenger of Allah and said,
"I have let my horse go, and thrown down my weapon, for the war has ended. There is no more fighting."
Then the Prophet said to him,
الاْنَ جَاءَ الْقِتَالُ لَا تَزَالُ طَايِفَةٌ مِنْ أُمَّتِي ظَاهِرِينَ عَلَى النَّاسِ يُزِيغُ اللهُ تَعَالَى قُلُوبَ أَقْوَام فَيُقَاتِلُونَهُمْ وَيَرْزُقُهُمُ اللهُ مِنْهُمْ حَتْى يَأْتِيَ أَمْرُ اللهِ وَهُمْ عَلَى ذلِكَ أَلَا إِنَّ عُقْرَ دَارِ الْمُوْمِنِينَ الشَّامُ وَالْخَيْلُ مَعْقُودٌ فِي نَوَاصِيهَا الْخَيْرُ إِلَى يَوْمِ الْقِيَامَة
Now the time of fighting has come. There will always be a group of my Ummah dominant over others. Allah will turn the hearts of some people away (from the truth), so they (that group) will fight against them, and Allah will bestow on them (war spoils) from them (the enemies) -- until Allah's command comes to pass while they are in that state. Verily, the center of the believers' abode is Ash-Sham. And goodness is tied around the horses' foreheads till the Day of Resurrection.
An-Nasa'i also recorded this narration.
Allah then says,
ذَلِكَ وَلَوْ يَشَاء اللَّهُ لَانتَصَرَ مِنْهُمْ
Thus, and had Allah so willed, He could have taken vengeance against them;
which means that had He so willed, He could have taken immediate vengeance against the disbelievers with a chastisement or exemplary punishment directly from Him.
وَلَكِن لِّيَبْلُوَ بَعْضَكُم بِبَعْضٍ
but (He lets you struggle) so as to test with one another.
meaning, He has ordered Jihad and fighting against the enemies in order to try you and test your affairs.
Allah also expresses His wisdom by the legislation of Jihad in the following two Surahs, Al `Imran and At-Tawbah, in which He says,
أَمْ حَسِبْتُمْ أَن تَدْخُلُواْ الْجَنَّةَ وَلَمَّا يَعْلَمِ اللَّهُ الَّذِينَ جَـهَدُواْ مِنكُمْ وَيَعْلَمَ الصَّـبِرِينَ
Or did you think that you would enter the Paradise before Allah had made evident those of you who fight in His cause and made evident those who are steadfast. (3;142)
قَـتِلُوهُمْ يُعَذِّبْهُمُ اللَّهُ بِأَيْدِيكُمْ وَيُخْزِهِمْ وَيَنْصُرْكُمْ عَلَيْهِمْ وَيَشْفِ صُدُورَ قَوْمٍ مُّوْمِنِينَ
وَيُذْهِبْ غَيْظَ قُلُوبِهِمْ وَيَتُوبُ اللَّهُ عَلَى مَن يَشَأءُ وَاللَّهُ عَلِيمٌ حَكِيمٌ
Fight them; Allah will then punishes them by your hands, disgrace them, grant you victory over them, satisfy the breasts of a believing people, and remove the fury of their (the believers') hearts. Allah turns in forgiveness to whom He wills; Allah is Knowing and Wise. (9;14-15)
Merit of the Martyrs
Since it is customary during wars that many of the believers die, Allah says;
وَالَّذِينَ قُتِلُوا فِي سَبِيلِ اللَّهِ فَلَن يُضِلَّ أَعْمَالَهُمْ
But those who are killed in the way of Allah, He will never let their deeds be lost.
which means that He would not let their good deeds go to waste, but would rather multiply and increase them. Some of them will continue being rewarded for their good deeds for the entire length of their stay in Al-Barzakh.
This has been mentioned in a Hadith recorded by Imam Ahmad in his Musnad on the authority of Kathir bin Murrah, who reported from Qays Al-Judhami, may Allah be pleased with him, that Allah's Messenger said,
يُعْطَى الشَّهِيدُ سِتَّ خِصَالٍ عِنْدَ أَوَّلِ قَطْرَةٍ مِنْ دَمِهِ تُكَفَّرُ عَنْهُ كُلُّ خَطِييَةٍ وَيَرَى مَقْعَدَهُ مِنَ الْجَنَّةِ وَيُزَوَّجُ مِنَ الْحُورِ الْعِين وَيَأْمَنُ مِنَ الْفَزَعِ الاَْكْبَرِ وَمِنْ عَذَابِ الْقَبْرِ وَيُحَلَّى حُلَّةَ الاِْيمَان
As the first drop of his blood gushes forth, a martyr is granted six merits;
all of his sins are forgiven,
he is shown his place in Paradise,
he is married to wide-eyed Huris,
he is secured from the great fear (on Judgement Day) and
the torment of the grave, and
he is adorned with the adornments of Iman.
Ahmad was alone in recording this Hadith.
Abu Ad-Darda, may Allah be pleased with him, reported that Allah's Messenger said,
يُشَفَّعُ الشَّهِيدُ فِي سَبْعِينَ مِنْ أَهْلِ بَيْتِه
A martyr is allowed to intercede for seventy members of his household.
This was recorded by Abu Dawud, and there are numerous other Hadiths mentioning the merits of the martyrs.
As for Allah's saying